Emergent Lorentz symmetry with vanishing velocity in a critical two-subband quantum wire.
Emergent Lorentz symmetry with vanishing velocity in a critical two-subband quantum wire.
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临界双子带量子线中速度消失的涌现洛伦兹对称性。
DOI：
10.1103/physrevlett.102.176404
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发表时间：
2008
影响因子：
8.6
通讯作者：
M. Garst
中科院分区：
文献类型：
--
作者：
Matthias Sitte;Achim Rosch;Julia S. Meyer;Konstantin Matveev;M. Garst
我们考虑了强相互作用下具有两个自旋极化电子子带的量子线。我们专注于量子相变时，第二子带开始得到作为门电压的函数填充。通过对有效哈密顿量进行单圈重整化群分析，我们将临界不动点理论确定为具有增强的SU（2）对称性和中心电荷3/2的共形场论。虽然固定点是洛伦兹不变的，但由于稍微不相关的算子导致临界比热系数发散，有效的“光速”在低能量下消失。
We consider a quantum wire with two subbands of spin-polarized electrons in the presence of strong interactions. We focus on the quantum phase transition when the second subband starts to get filled as a function of gate voltage. Performing a one-loop renormalization group analysis of the effective Hamiltonian, we identify the critical fixed-point theory as a conformal field theory having an enhanced SU(2) symmetry and central charge 3/2. While the fixed point is Lorentz invariant, the effective "speed of light" nevertheless vanishes at low energies due to marginally irrelevant operators leading to a diverging critical specific heat coefficient.